The timing belt on your car, van or truck, does a very important job.
But because it’s something which only needs to be replaced every few years or so, it’s a job which can be easily overlooked.
That could be a big and costly mistake.
Because the job of a timing belt is essentially, to keep a number of important parts moving in synchronisation, if it fails the consequences can be immediate.
A timing belt connects the camshaft to the crankshaft and keeps the engine valves opening and closing in time with the movement of the pistons. The belt itself is black toothed rubber belt which because of wear needs to be replaced at regular intervals. Also at this time it is important to also change the water pump as it is driven by the belt so disturbing the pump will almost immediately start leaking engine coolant.
A belt failure damages the engine because the belt controls the timing of the opening and closing of the cylinder valves. Once the belt fails, the valves will remain in the position they were in at the instant the belt fails; but the pistons will continue to move, because of their momentum, and hit and damage any open valves. Sometimes, the pistons will hit the valves so hard that the camshaft will be damaged as well as the valves.